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Yellowing leaves that drop prematurely are an unsettling sign that something is amiss with your cherry tree. Cherry trees are a member of the Prunus genus, and other members include almonds, peaches, plums and nectarines. The cherry is susceptible to various problems that attack the tree, causing its leaves to discolor and fall. Identifying the problem will allow you to provide proper treatment and help save the cherry tree.

Cherry Leaf Spot

Caused by the fungus Blumeriella jaapii, cherry leaf spot targets the foliage of cherry trees but can also infect stems and fruit. Small purple spots on the tops of leaves are generally the first symptom of this fungal disease. The spots turn brown and begin to enlarge and collapse, leaving a hole in the foliage. Older leaves will yellow and drop from the branches, and the cherry tree can lose all its leaves, which weakens the fruit tree and increases its susceptibility to cold damage. Properly timed applications of fungicide will help prevent cherry leaf spot. Start fungicide preventive sprays at the petal fall stage and repeat every seven days until harvest. West Virginia University's Davis College of Agriculture, Natural Resources, and Design recommends applying one or two applications after harvest, starting three weeks after the harvest date. It also suggests spraying only one side of the tree when applying the fungicides and alternating sides with each application.

Verticillium Wilt

Yellowing of the current season’s leaves at the bottom of the tree is a telltell sign of verticillium wilt. The infection spreads upward, infecting twigs and branches, causing them to die. The yellow leaves drop and by fall, leaving only the upper leaves of the cherry tree on the branches. This fungal disease may attack only one side of the cherry tree while the other side appears untouched by the fungus. Verticillium wilt is caused by a soil-borne fungal pathogen that can live in the soil for years. Controlling verticillium wilt relies on proper prevention by planting cherry trees in pathogen-free soil. In addition, regularly remove weeds, water properly, avoid excessive nitrogen fertilizers and refrain from over-pruning.

Phytophthora Root and Crown Rot

Several species of the fungal pathogen Phytophthora cause Phytophthora root and crown rot in cherry trees. The first symptoms of this disease may resemble mechanical girdling, winter injury or damage from rodents. When warm weather arrives, infected cherry trees decline rapidly and the leaves begin to dull and discolor, turning yellow, red or purple. Infected trees may die the same year the infection began or years later. A dark, gummy sap may seep out of the trunk and removing the outer bark reveals discoloration. Planting cherry trees in well-drained soil helps to prevent Phytophthora infections. If the tree is showing signs of infection, remove the soil away from the base and main roots of the cherry tree. This will help dry the crown tissue and the tree might survive this disease.

Armillaria Root Rot

Also called oak root fungus, Armillaria root rot symptoms vary. When the fungal disease rapidly develops, it causes stunted leaves that yellow and drop off the branches. If the disease progresses slowly, the leaves can prematurely show their fall coloring. Healthy roots develop dark-colored rhizomorphs that look similar to shoestrings and grow on the surface of the roots. Infected trees may be saved if the disease hasn’t girdled half of the crown’s circumference. Push soil piled around the crown away from the tree. This will air out the exposed crown and aid in drying. Remove tissue and bark infected with a leathery whitish fungal growth. The University of California Integrated Pest Management Program recommends removing trees with more than half of their crown infected.

About the Author

Amanda Flanigan began writing professionally in 2007. Flanigan has written for various publications, including WV Living and American Craft Council, and has published several eBooks on craft and garden-related subjects. Flanigan completed two writing courses at Pierpont Community and Technical College.